New promising Big Data sources are becoming available in the public transport industry. This data provides insights into both passenger flows and vehicle performance and is of great help to optimize public transport services. Traffic models are able to quickly process this data and to present it on a geographical layer. It enables to evaluate ridership and to compare it with the use of other modes as car and bike traffic. Finally, what-if predictions are available to gain insights into the expected level of cost coverage, service and ridership. These steps are of great support to optimize the public transport network and timetable design as well as its operations. This presentation reveals such opportunities for public transport systems.